How to do: Standing Arnold Press

Set up for the exercise by grabbing a pair of dumbbells and standing straight up with your feet around shoulder width apart.
Raise the dumbbells to shoulder height on each side, and twist so that your palms are facing your body.
The dumbbells should now be positioned in front of your shoulders. Your back should be straight and there should be a slight bend in your knees. This is the starting position for the exercise.
Keeping your eyes facing forwards, slowly raise the dumbbells above your head while turning your wrists so that your palms are now facing forward (away from your body).
Keep raising the weight until your arms are almost fully extended.
Do not pause at the top of the movement, and begin lowering the dumbbells back down to the starting position - twisting at the wrist until your palms are facing your body once again.
Repeat this movement for the desired amount of reps.